Discharge lamps which provide for discharges in which the discharge beam is controlled by providing a focusing or beam forming element, such as a diaphragm between the anode and cathode, are known. The diaphragm, with an opening therethrough, being subject to the discharge itself will become hot. It was previously been proposed to enclose the electrode system of discharge lamps in a metallic housing, the outer surface of which is engaged by resilient clips, such as spring clips, bails, or spring sheets. Since the housing is of metal, the resilient elements engaging the metal housing will provide for some heat conduction from the housing. Such a construction is described in German Patent DE-PS No. 11 52 482.